They capture the diseased, wounded and weaker prey thus letting only the strongest survive and thus maintaining a healthy population and keeping up the genetic quality of their prey species.

Then King Humayun, annoyed by the Pathans, went abroad [to Persia]; and at last, returning from thence, he punished the surviving [Pathans], and no rebel remained to raise strife or disturbance.

It is not merely that among competing businesses, the larger showing themselves the stronger survive, and the smaller, out-competed disappear.

All now are vanish'd; virtue sole survives, Immortal, never-failing friend of man His guide to happiness on high.